YOU SAID:

I am goingto an amusment park wanna Join?

INTO JAPANESE

遊園地に行く予定なのですが、参加しませんか？

BACK INTO ENGLISH

We are planning to go to an amusement park, would you like to join us?

INTO JAPANESE

遊園地に行く予定なのですが、一緒に行きませんか？

BACK INTO ENGLISH

I'm planning to go to an amusement park, would you like to go with me?

INTO JAPANESE

遊園地に行く予定なのですが、一緒に行きませんか？

BACK INTO ENGLISH

I'm planning to go to an amusement park, would you like to go with me?